Comment 16 for bug 1478367

> All packages that use glibmm would be required to be updated in Ubuntu to build with C++11 for this transition

It's the libstdc++ ABI break that causes the need for apps to be rebuilt. glibmm using C++11 in its API should not require anything to be rebuilt, and we'd definitely like to know if it does. I wouldn't call use of C++11 a transition.

It's inconvenient for you that the ABI break (libstdc++) and API change (glibmm using C++11) happened at around the same time in Ubuntu, but now that you've now managed to rebuild (because of the libstdc++ ABI break), for instance, subtitleeditor, with glibmm 2.44 (without C++11), updating glibmm to 2.45/46 should have no effect whatsoever on how well the already-built subtitleeditor works.